Ultrapeer has been disabled all along and no, I don't use a personal firewall. I've had a look at the Sharing section of the System Preferences but am not sure what you mean about opening port 6346, as there are no port options.

I haven't changed any settings nor installed any apps that resulted in this problem. The strange thing is that whenever I uninstall/reinstall Limewire, it works fine for a few sessions, then the problem creeps back in.

When I listen to the signal (via my phone) during one of these 'freezes' it sounds like the signal has entered a loop with a repeating signal being received.